Lancets and lancing devices are utilized for penetrating the skin of a human or animal subject at a lancing site to obtain a sample of blood or other body fluid for medical testing, as in blood-typing or blood-glucose testing. Known lancing devices commonly include a housing containing a drive mechanism, a charging mechanism for energizing the spring or other drive means of the drive mechanism, and a release mechanism for releasing the drive mechanism upon actuation. A lancet is typically propelled by the drive mechanism from a retracted position shielded within the housing to an extended position wherein a sharp tip portion of the lancet projects from the housing to prick the subject's skin at a desired lancing site. An ejection mechanism can optionally be included for discharge of a used lancet from the lancing device.
The lancet may be a disposable component that is removably mounted into a receiver or lancet carrier portion of the drive mechanism of a lancing device. A used lancet typically is removed from the lancet carrier after sampling for disposal. A new, sterile lancet is then replaced into the lancet carrier for further sampling. Lancets typically comprise a sharp metal tip in the form of an elongate needle or blade, for example formed of stainless steel. The needle or blade is typically embedded in a plastic body that has a size and shape configured for releasable engagement with the receiver or lancet carrier of a lancing device. The sharp tip of the lancet is commonly embedded in a removable plastic endcap to maintain sterility and prevent inadvertent sticks prior to use. The endcap may be replaceable onto the lancet after use to re-cover the sharp lancet tip for safety and hygienic purposes.
In alternate “single-use” embodiments, the lancet is not intended for removal and replacement, and the entire lancing device and lancet are disposed of after a single use. Single use devices commonly include re-use prevention mechanisms to resist attempts to utilize the device for more than one sampling procedure.
In order to retain the lancet needle securely in place in the lancet body during de-capping, when twisting and pulling forces are commonly imparted on the lancet needle, lancet needles traditionally have a length that corresponds to the length of the plastic lancet body and the distance to which the tip of the lancet needle extends beyond the lancet body, so that the needle has enough contact surface area within the lancet body to resist detachment or loosening of the needle from the plastic body. Also, typical lancet manufacturing processes utilize longitudinally spaced contact points for holding the lancet needle within the mold during molding of the lancet body and maintaining proper axial alignment of the lancet needle. As such, it has until now been considered counterintuitive to those of ordinary skill in the art to seek to significantly reduce the length of the lancet needle within a lancet.
Continuing needs exist for improvements to lancet technology. It is to the provision of improved lancet needles and lancets that the present invention is primarily directed.